91
Computing the Cycle Time
Section 2-7
2-7
Computing the Cycle Time
2-7-1
CPU Unit Operation Flowchart
The CPU Unit processes data in repeating cycles from the overseeing pro-
cessing up to peripheral servicing as shown in the following diagram.
NO
YES
Power ON
Checks Unit connection status.
Checks hardware and user
program memory.
Executes user program (i.e.,
executes READY cyclic tasks).
Waits until the set cycle time
has elapsed.
Calculates cycle time.
Sets error flags.
Performs I/O refreshing.
Services peripheral devices.
Peripheral
servicing
I/O
refreshing
Cycle time
calculation
Program
execution
Overseeing
processing
PLC
cycle
time
Startup
initialization
Check OK?
ERR/ALM
indicator ON or
flashing?
End of program?
Flashing
(nonfatal error)
ON (fatal error)
Error
Normal
Содержание CP1H CPU UNITS - PROGRAMMING 05-2007
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Страница 34: ...xxxiv Conformance to EC Directives 6...
Страница 174: ...140 CP series Expansion I O Unit Wiring Section 3 6...
Страница 370: ...336 Analog I O XA CPU Units Section 5 5...
Страница 552: ...518 Trouble Shooting Section 8 7...
Страница 595: ...561 Sample Application Section 9 12 Network Settings Network Tab Network Settings Driver Tab...
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Страница 642: ...608 Standard Models Appendix A...
Страница 643: ...609 Appendix B Dimensions Diagrams X XA and Y CPU Units 90 100 110 140 150 8 85 Four 4 5 dia holes...
Страница 652: ...618 Dimensions Diagrams Appendix B...
Страница 745: ...711 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Страница 746: ...712 Connections to Serial Communications Option Boards Appendix F...
Страница 776: ...742 PLC Setup Appendix G...
Страница 778: ...744 Specifications for External Power Supply Expansion Appendix H...
Страница 786: ...752 Revision History...